1) Field of the Invention
The present invention relates to corticosteroid-containing ointments, and more specifically to corticosteroid-containing ointments which contain deprodone propionate as an effective ingredient, can exhibit its effects to the maximum extent and over a prolonged period of time, do not have skin irritation, and are physicochemically stable.
2) Description of the Related Art
Corticosteroids have heretofore been employed widely as remedial agents in the field of dermatology because they exhibit even in a small amount strong therapeutic effects for inflammatory and allergic skin diseases and have fast-acting property compared with other medicaments.
When a corticosteroid is used as an external preparation for a localized disease in the field of dermatology, it is often applied in the form of an ointment since an ointment has excellent protective and anti-inflammatory action for the skin and gives very little irritation or contact dermatitis to the skin.
The corneum in the surface of the skin however inherently functions as a barrier in order to prevent penetration of foreign substances from the outside into the body. This has led to the problem that sufficient percutaneous absorption cannot be achieved with an ointment containing a steroid ingredient simply mixed in a base which has conventionally been employed in external preparations.
To improve this problem, various percutaneous absorption promoters such as 1-dodecylazacycloheptan-2-one, dimethylsulfoxide and dimethylformamide have been used in recent years. These promoters are however not considered sufficient in safety and feeling of use.
It is also practiced to use a corticosteroid having strong effects so as to tentatively improve the percutaneous absorption or to increase the concentration of a corticosteroid so as to increase the therapeutic effects. These methods are however accompanied by the problem of side effects because the influence to the whole body or a part thereof increases in proportion to the effects and concentration of the corticosteroid.
It has therefore been desired to develop a corticosteroid-containing ointment which has high curative effects and which gives less side effects to the whole body or a part thereof and has higher safety.
It is however to be noted that the curative effects of an ointment significantly vary depending on the kind of its base and the like even when the ointment contains the same effective ingredient at the same concentration and an ointment having excellent curative effects and little side effects can be obtained for the first time when its effective ingredient and its base match well in physicochemical properties.